Pro's and cons of building a 6.4

dangerous06

dangerous06

diesel tech
Would like a few motor guru's to chime in. I've heard it both ways so what is the true story?! Is it worth building? Is the 6.7 head better than the 5.9?
With Carrillo making rods for this build now it would seem it's popular.
I've already got the 6.7 motor and 5.9 crank. Running the 5.9 ECM and early injectors. Am I missing anything?
 
You can run larger valves with the 6.7 head and 4.2 bore, an advantage over everything else. Besides lacking displacement I would rather gain some reliability by using a 5.9 crank to reduce stress in the bottom end.
 
Not sure how a 6.7 head allows you to go any bigger on the valves than a 5.9 head sitting on the same bore??

Personally I have had better success with 5.9 heads but just could be dumb luck.
 
For general info:
6.7 and 5.9 rods are the same length.
Heads are the same except for the steam holes.
Now a few questions!
What are the steam holes for and where exactly are they?
What year did they start coating the 6.7 pistons? and are the marine pistons fully coated and anybody have a part number?!
 
6.7 are siamese bores, so coolant can't flow between the cylinders. So now you have a lot of surface area and little water, so its gonna boil there. The holes let it flow up into the head instead of being trapped at the deck and cause hot spots. They are on both sides of the block between each cylinder, where the cylinder walls converge. If you pull the oil cooler off the side of the block, you'll see exactly whats going on.
 
So the 5.9 head needs to be drilled to use the steam holes! I finally got my hands on the 6.7 just a quick look over I noticed the steam holes and the crazy smog crap! What is with the double walled oil pan and the sound padding on the drivers side? Are they trying to quiet it down? Also all the piston skirts are rubbed bad?? Think a quick hone will clean up the cylinders? Nothing to grab a nail just can see the score RUB marks on the walls!
The Fuel rail is crazy big compared to the 5.9. Are the CP3's the same? Can a 5.9 run the 6.7 CP3 or do I need to change it out? WAS going to anyways but just wondering?!
The heads are Identical after removing all the crap So I'll just put a set of 103# springs on it and call it a day.
Anybody want to buy a 6.7 crank? I Need to pay for my Carrillo rods!
 
I love the 6.7 pans way stouter and less noise.

The padding I was told was to help reduce harmonics for the ECM's.

The pumps are not the same but you can run a 6.7 on the 5.9 with some tweaking of the rail feed line however I prefer the CP3.

The 6.7 injectors will not seat in a 5.9L head properly however you can fit the 5.9 injectors in a 6.7 head.
 
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